Puberty Syndrome—a rumored, mysterious syndrome that only affects people during puberty. For example, a bunny girl — named Sakurajima Mai — suddenly appeared in front of Sakuta Azusagawa. For some reason, the people around Mai can no longer see her. Thus, Sakuta sets out to solve this mystery. While doing so, he gains feelings for Mai. Furthermore, while helping Mai through her predicament, he encounters other women afflicted with the elusive disease. (by Jon Smith)